HR: 15:45h
AN: NB14A-02    [Abstracts]
TI: Long-Term Studies of the Effects of Salmon Spawners on Stream Ecosystems
AU: * Chaloner, D T
EM: chaloner.1@nd.edu
AF: University of Notre Dame, Department of Biological Sciences, Notre Dame, IN 46556 United States
AU: Lamberti, G A
EM: lamberti.1@nd.edu
AF: University of Notre Dame, Department of Biological Sciences, Notre Dame, IN 46556 United States
AU: Cak, A D
EM: acak@indiana.edu
AF: Indiana University, School of Public and Environmental Affairs, Bloomington, IN 47405 United States
AU: Edwards, R T
EM: rtedwards@fs.fed.us
AF: USDA Forest Service, Pacific Northwest Research Station, Juneau, AK 99801 United States
AB: To determine the ecological effects of salmon-derived nutrients (SDN) transported into fresh waters by spawning adult Pacific salmon (Oncorhynchus spp.), we monitored several ecological parameters in Fish Creek, Southeast Alaska from 2000 to 2004. Pink and chum salmon spawn in the lower reach of Fish Creek, but cannot move further upstream because of a waterfall, 4 km from saltwater. We estimated spawner densities and measured dissolved nutrient concentrations and epilithon abundance before, during, and after the salmon run, in reaches above and below the waterfall barrier. Salmon spawners increased streamwater concentrations of ammonium (2.3 - 148x) and soluble reactive phosphorus (0.4 - 17x), and epilithon chlorophyll a (14 - 29x) and ash-free dry mass (1.4 - 4x) in lower reaches. However, the duration and magnitude of these effects varied widely among years, and did not appear to vary solely with spawner densities. Our results suggest that although SDN can stimulate primary production through increased nutrient concentrations, other environmental factors, such as temperature, irradiance, and discharge, can modulate the influence of salmon spawners on stream ecosystems. To better assess the ecological influence of SDN, future studies should consider the influence of key environmental factors and their temporal and spatial dynamics.
DE: 9810 New fields (not classifiable under other headings)
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly